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First principles thinking is the superpower that many attribute to Elon Musks success. With Tesla he revolutionized the automotive industry. First doubted by many that he will be able to create an electric car company at all, now many other car manufacturers followed his lead in committing to only building electric cars. With SpaceX Elon Musk reduced the cost of bringing payloads to orbit by 10 fold by making boosters land back on land and reusable for future flights. With that as well experts doubted that it will be possible to land a rocket at all. But Elon Musk’s first principles thinking dictated that if it didn’t violate the laws of physics, it must be possible. After multiple attempts, he successfully demonstrated the viability of this innovative approach.

So what is first principles thinking and how can you become a first principles thinker?

What is First Principles Thinking

First principles comes from philosophy and physics. There a first principle is a fundamental truth that can not be broken down any further. From this fundamental truth you can reason up and explain the processes.

Elon Musk about his way of thinking at TED 1:

Well, I do think there’s a good framework for thinking. It is physics. You know, the sort of first principles reasoning. What I mean by that is, boil things down to their fundamental truths and reason up from there, as opposed to reasoning by analogy. Through most of our life, we get through life by reasoning by analogy, which essentially means copying what other people do with slight variations. And you have to do that. Otherwise, mentally, you wouldn’t be able to get through the day. But when you want to do something new, you have to apply the physics approach. Physics is really figuring out how to discover new things that are counterintuitive, like quantum mechanics.

First Principles Thinking in Philosophy: Aristotle’s Approach

picture of Aristoteles with an abstract concept of the unmoved mover in the background

First principles thinking has its roots in the philosophical teachings of Aristotle, who used this approach to uncover fundamental truths and build a coherent understanding of the world. He called these fundamental truths “archai,” which translates to “beginnings” or “principles.” In his philosophical inquiries, Aristotle sought to understand the essence of things by identifying their fundamental building blocks and deriving knowledge from these basic truths.

To Aristotle, first principles were self-evident and indubitable truths that could not be derived from any other principles. He believed that by starting with these first principles, one could logically deduce other truths and build a solid foundation for understanding the world. Aristotle’s process of reaching these first principles involved a technique called “dialectic,” which was an exploration of different opinions and viewpoints through dialogue and questioning. By engaging in dialectic, Aristotle aimed to peel away the layers of complexity and ambiguity, ultimately revealing the foundational principles that underlie various phenomena.

One famous example of Aristotle’s application of first principles thinking is his concept of the “unmoved mover.” He reasoned that if everything in the universe is in motion, there must be a cause for this motion, and that cause must be something that is itself unmoving. By identifying the unmoved mover as a first principle, Aristotle developed a comprehensive metaphysical framework that accounted for the motion and change observed in the world.

Descartes’ Radical Doubt: “I think, therefore I am”

René Descartes, the 17th-century French philosopher, began his philosophical journey by doubting everything he knew or believed to be true. He questioned the reliability of his senses, the existence of the external world, and even the validity of his own thoughts. Through this process of relentless questioning and doubt, Descartes aimed to identify the most fundamental and self-evident truths, from which he could construct a solid and unshakable foundation for his philosophical system.

In his quest for certainty, Descartes arrived at the realization that the very act of doubting and thinking proved his own existence. He reasoned that even if he doubted everything else, he could not doubt the fact that he was doubting and thinking. This simple yet profound insight led to his famous declaration, “I think, therefore I am.”

This statement encapsulates Descartes’ first principles approach to knowledge and understanding. By questioning everything he identified a fundamental and self-evident truth: his own existence as a thinking being. From this indubitable starting point, Descartes went on to build a comprehensive philosophical system that encompassed the nature of reality, the existence of God, and the relationship between the mind and the body.

picture of Descartes looking doubting at the viewer

The Power of First Principles in Physics

In the late 17th century, a young and inquisitive man named Isaac Newton was studying at the University of Cambridge. A brilliant and curious student, Newton was captivated by the mysteries of the natural world and constantly sought to uncover the fundamental principles that governed it.

One day, as Newton sat beneath an apple tree in the university’s garden, he witnessed an apple falling from a branch above. This simple event sparked a profound question in his mind: what force causes objects to fall towards the ground? Inspired by this question, Newton embarked on a journey to discover the underlying principles that governed the motion of objects on Earth and in the heavens.

Through diligent research and experimentation, Newton formulated his groundbreaking laws of motion, which described the relationship between the forces acting on an object and its motion. Armed with these principles, Newton sought to apply them to the celestial realm and understand the motion of the planets and other celestial bodies.

Focusing on the Moon, Newton wondered if the same force that caused the apple to fall from the tree could also be responsible for the Moon’s orbit around the Earth. To investigate this hypothesis, he considered the gravitational force acting on the Moon and the force required to keep it in orbit.

picture of an apple falling from a tree, the moon directly behind it

Through a series of calculations, Newton found that the force needed to maintain the Moon’s orbit was indeed proportional to the gravitational force acting upon it, suggesting that a single force - gravity - was responsible for both the motion of the apple falling to the ground and the Moon’s orbit around the Earth. This revelation was a groundbreaking discovery that unified the understanding of forces acting on both terrestrial and celestial objects.

Newton’s insight led to the formulation of his law of universal gravitation, which stated that every object with mass attracts every other object with mass, with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them. This law provided a unified framework for understanding the motion of objects on Earth and in the heavens, forever changing the way we perceive the universe.

Through his relentless pursuit of knowledge and his ability to reason up from first principles, Isaac Newton revolutionized our understanding of the natural world. His laws of motion and law of universal gravitation continue to serve as foundational principles in physics, shaping our comprehension of the cosmos and inspiring generations of scientists and thinkers to come.

General Approach to First Principles in Physics

The first step in applying first principles thinking in physics is to formulate a hypothesis for a potential fundamental law. This often involves observing the natural world, identifying patterns, and devising a possible explanation or rule that governs the observed behavior. Physicists draw upon their knowledge of existing theories, as well as their creativity and intuition, to propose new hypotheses that can be tested through experimentation.

Once a hypothesis has been formulated, physicists design and conduct experiments to test its validity. These experiments must be carefully controlled and repeatable, allowing for the accurate measurement of relevant variables and the elimination of potential confounding factors. By comparing the experimental results with the predictions made by the hypothesis, physicists can assess whether the proposed law aligns with the observed data.

If the experimental results consistently support the hypothesis, it may become accepted as a first principle or fundamental law in physics. However, if the results contradict the hypothesis, it may need to be revised or discarded in favor of an alternative explanation.

Developing First Principles Thinking Skills

First principles thinking is a powerful mental tool that can be applied in various aspects of life, not just in physics or philosophy. By learning to think in first principles, you can develop the ability to break down complex problems, identify their fundamental truths, and reason up from there to find innovative and effective solutions. Here are some techniques to help you cultivate first principles thinking:

  1. Ask “why” multiple times: When faced with a problem or question, ask “why” several times to peel back the layers of complexity and uncover the underlying principles. By questioning assumptions and diving deep into the core of the issue, you can identify the fundamental truths from which you can reason up and develop a solution.
  2. Embrace doubt and skepticism: Cultivate a mindset of doubt and skepticism when tackling problems or beliefs. By questioning everything, even your own thoughts, you can identify the most fundamental and self-evident truths as your starting point. This practice enables you to build a solid foundation for understanding and solving problems, grounded in first principles thinking.
  3. Challenge analogies: Many of our beliefs are based on analogies that may not be entirely accurate or relevant. To think in first principles, it’s essential to identify and challenge these analogies, scrutinizing their validity and questioning whether they truly apply in the context of the problem at hand.
  4. Understand analogies and mental models: While first principles thinking encourages reasoning from fundamental truths rather than relying on analogies, it’s still valuable to be familiar with various analogies and mental models. These can serve as useful starting points for your reasoning or doubting process, helping you to identify patterns and connections between seemingly unrelated phenomena. Once you’ve drawn upon these analogies and models, you can then apply first principles thinking to refine and develop your understanding further.
  5. Break down problems into their basic components: By dissecting complex issues into smaller, more manageable parts, you can analyze each component individually and identify the fundamental principles that govern them. This process will help you gain a deeper understanding of the problem and enable you to build a solution from the ground up.
  6. Envision the ideal solution and work backwards: Rather than relying solely on familiar tools and methods, take a moment to imagine the perfect solution to the problem at hand. Ask yourself what the ideal outcome would look like and what characteristics it would possess. Once you have a clear vision of the desired solution, work backward to determine the necessary steps and resources to achieve it. This approach encourages you to think beyond the limitations of conventional methods, fostering creativity and innovation in your problem-solving process.
  7. Embrace curiosity and continuous learning: Developing first principles thinking requires a strong sense of curiosity and a commitment to learning. By nurturing your curiosity and constantly seeking out new knowledge, you’ll be better equipped to identify fundamental truths and reason up from them to tackle complex challenges.

First Hand Examples of First Principles Thinking

Here are a few first hand examples of first principles thinking from Elon Musk. Notice how he applies the skills outlined above.

In the video below he explains how to think from first principles:

  • Don’t brake the laws of physics.
  • Think about how things change when you scale something to a very large or very low number. If a part is still expensive when you produce a million a year then the reason is its design.
  • Anything at volume can be made for costs that asymptotically approach the costs of the raw materials plus intellectual property license rights.
  • Instead of using the tools and methods that you already know ask yourself: What would be the perfect solution and how can you get to that.

Next he explains how people reason from analogy:

Batteries are expensive and they will always be, because the are expensive right now. But if you break down the material costs of batteries, then you see that these are really cheap and it is the assembly that is expensive. These costs can be reduced by improving the assembly process and increasing the scale.

On the costs of rockets. Again he breaks down the costs of a rocket to the cost of its components and the cost of assembly.

Elon about what a company and profit is:

A company is a assembly of people who gather together to create and deliver a product or service. A company has no value in itself, only in being an effective allocator to create goods and services that are of greater value than the costs of the inputs. Profit is that over time the value of the outputs is greater than the value of the inputs.

Elon about how he is able to attract talent:

If you wanna recruit people that are really talented and driven you have to state the mission and have a convincing argument for why it matters. There a three major things in terms of motivation:

  • A person is enjoying the work itself intrinsically
  • The financial compensation is fair and good
  • The best people wanna know if what they are doing is going to matter, will people notice their work or will the world be different


In conclusion, first principles thinking is a powerful and transformative approach to problem-solving that has been employed by some of the most brilliant minds in history, including Aristotle, Isaac Newton, and Elon Musk. This way of thinking transcends disciplines and can be applied to various aspects of life, from philosophy and physics to business and everyday challenges. By cultivating this mindset and applying it in our own lives, we can unlock our own potential for creative problem-solving and embark on a journey of continuous growth and learning.


  1. Elon explains first principles thinking at TED: https://youtu.be/IgKWPdJWuBQ?t=1096